The semiconductor industry has experienced rapid growth due to ongoing improvements in the integration density of a variety of electronic components (e.g., transistors, diodes, resistors, capacitors, etc.). For the most part, improvement in integration density has resulted from iterative reduction of minimum feature size, which allows more components to be integrated into a given area. As the demand for shrinking electronic devices has grown, a need for smaller and more creative packaging techniques of semiconductor dies has emerged. An example of such packaging systems is Package-on-Package (PoP) technology. In a PoP device, a top semiconductor package is stacked on top of a bottom semiconductor package to provide a high level of integration and component density. PoP technology generally enables production of semiconductor devices with enhanced functionalities and small footprints on a printed circuit board (PCB).
Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.
Before addressing the illustrated embodiments specifically, certain advantageous features and aspects of the embodiments will be addressed generally. In some aspects, various example embodiments may enable an extremely thin package profile integrating memory and logic chips, for example. Improved memory capacity and bandwidth may be achieved in thin-profile stacked fan-out packages. A stacked fan-out package may use through insulating vias (TIVs) as an option for electrical routing in lieu of through silicon vias (TSVs), thus reducing silicon asset penalty, reducing manufacturing costs, and increasing thermal dissipation performance. In some embodiments, the stacked fan-out package may be further integrated with other semiconductor devices, such as logic devices, for forming an integrated package that can have high performance, enhanced thermal management, and reduced manufacturing cost.
The wafer 30 may be processed according to applicable manufacturing processes to form integrated circuits in the integrated circuit dies 50. For example, each of the integrated circuit dies 50 includes a semiconductor substrate 52, such as silicon, doped or undoped, or an active layer of a semiconductor-on-insulator (SOI) substrate. The semiconductor substrate 52 may include other semiconductor materials, such as germanium; a compound semiconductor including silicon carbide, gallium arsenic, gallium phosphide, indium phosphide, indium arsenide, and/or indium antimonide; an alloy semiconductor including SiGe, GaAsP, AlinAs, AlGaAs, GaInAs, GaInP, and/or GaInAsP; or combinations thereof. Other substrates, such as multi-layered or gradient substrates, may also be used. The semiconductor substrate 52 has an active surface (e.g., the surface facing upwards in
Devices 54 (represented by a transistor) may be formed at the front surface of the semiconductor substrate 52. The devices 54 may be active devices (e.g., transistors, diodes, etc.), capacitors, resistors, etc. An inter-layer dielectric (ILD) 56 is over the front surface of the semiconductor substrate 52. The ILD 56 surrounds and may cover the devices 54. The ILD 56 may include one or more dielectric layers formed of materials such as Phospho-Silicate Glass (PSG), Boro-Silicate Glass (BSG), Boron-Doped Phospho-Silicate Glass (BPSG), undoped Silicate Glass (USG), or the like.
Conductive plugs 58 extend through the ILD 56 to electrically and physically couple the devices 54. For example, when the devices 54 are transistors, the conductive plugs 58 may couple the gates and source/drain regions of the transistors. The conductive plugs 58 may be formed of tungsten, cobalt, nickel, copper, silver, gold, aluminum, the like, or combinations thereof. An interconnect structure 60 is over the ILD 56 and conductive plugs 58. The interconnect structure 60 interconnects the devices 54 to form an integrated circuit. The interconnect structure 60 may be formed by, for example, metallization patterns in dielectric layers on the ILD 56. The metallization patterns include metal lines and vias formed in one or more low-k dielectric layers. The metallization patterns of the interconnect structure 60 are electrically coupled to the devices 54 by the conductive plugs 58. In some embodiments, passive devices are also formed in the interconnect structure 60.
Pads 62, such as aluminum pads, to which external connections are made. The pads 62 are on the active side of the integrated circuit dies 50, such as in and/or on the interconnect structure 60. One or more passivation films 64 are on the integrated circuit dies 50, such as on portions of the interconnect structure 60 and pads 62. Openings extend through the passivation films 64 to the pads 62. Die connectors 66, such as conductive pillars (for example, formed of a metal such as copper), extend through the openings in the passivation films 64 and are physically and electrically coupled to respective ones of the pads 62. The die connectors 66 may be formed by, for example, plating, or the like. The die connectors 66 electrically couple the respective integrated circuits of the integrated circuit dies 50.
Optionally, solder regions (e.g., solder balls or solder bumps) may be disposed on the pads 62. The solder balls may be used to perform chip probe (CP) testing on the integrated circuit dies 50. CP testing may be performed on the integrated circuit dies 50 to ascertain whether an individual integrated circuit die 50 is a known good die (KGD). Thus, only integrated circuit dies 50, which are KGDs, undergo subsequent processing are packaged, and dies, which fail the CP testing, are not packaged. After testing, the solder regions may be removed in subsequent processing steps.
A dielectric layer 68 may (or may not) be on the active side of the integrated circuit dies 50, such as on the passivation films 64 and the die connectors 66. The dielectric layer 68 laterally encapsulates the die connectors 66, and the dielectric layer 68 is laterally coterminous with the integrated circuit dies 50. Initially, the dielectric layer 68 may bury the die connectors 66, such that the topmost surface of the dielectric layer 68 is above the topmost surfaces of the die connectors 66. In some embodiments where solder regions are disposed on the die connectors 66, the dielectric layer 68 may bury the solder regions as well. Alternatively, the solder regions may be removed prior to forming the dielectric layer 68. Although
The dielectric layer 68 may be a polymer such as PBO, polyimide, BCB, or the like; a nitride such as silicon nitride or the like; an oxide such as silicon oxide, PSG, BSG, BPSG, or the like; the like, or a combination thereof. The dielectric layer 68 may be formed, for example, by spin coating, lamination, chemical vapor deposition (CVD), or the like. In some embodiments, the die connectors 66 are exposed through the dielectric layer 68 during the formation of the integrated circuit dies 50. In some embodiments, the die connectors 66 remain buried and are exposed during a subsequent process for packaging the integrated circuit dies 50. Exposing the die connectors 66 may remove any solder regions that may be present on the die connectors 66. In some embodiments, after the die connectors 66 and the dielectric layer 68 are formed, the wafer 30 may be singulated according to the scribe line 70, so that the integrated circuit dies 50 may be separated and can be picked up individually.
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The formation of the redistribution structure 112 may include depositing the dielectric layer 114 on the top surfaces of the encapsulant 110, the die connectors 66, and the dielectric layer 68. In some embodiments, the dielectric layer 114 is formed of a photosensitive material such as PBO, polyimide, BCB, or the like, which may be patterned using a lithography mask. The dielectric layer 114 may be formed by spin coating, lamination, CVD, the like, or a combination thereof. The dielectric layer 114 is then patterned. The patterning forms openings exposing portions of the die connectors 66. The patterning may be by an acceptable process, such as by exposing and developing the dielectric layer 114 to light when the dielectric layer 114 is a photosensitive material or by etching using, for example, an anisotropic etch.
The metallization pattern 116 is then formed. The metallization pattern 116 includes conductive elements extending along the major surface of the dielectric layer 114 and extending through the dielectric layer 114 to physically and electrically coupled to the first device die 50A. As an example to form the metallization pattern 116, a seed layer is formed over the dielectric layer 114 and in the openings extending through the dielectric layer 114. In some embodiments, the seed layer is a metal layer, which may be a single layer or a composite layer comprising a plurality of sub-layers formed of different materials. In some embodiments, the seed layer comprises a titanium layer and a copper layer over the titanium layer. The seed layer may be formed using, for example, PVD or the like. A photoresist is then formed and patterned on the seed layer. The photoresist may be formed by spin coating or the like and may be exposed to light for patterning. The pattern of the photoresist corresponds to the metallization pattern 116. The patterning forms openings through the photoresist to expose the seed layer. A conductive material is then formed in the openings of the photoresist and on the exposed portions of the seed layer. The conductive material may be formed by plating, such as electroplating or electroless plating, or the like. The conductive material may comprise a metal, like copper, titanium, tungsten, aluminum, or the like. The photoresist and portions of the seed layer on which the conductive material is not formed are removed. The photoresist may be removed by an acceptable ashing or stripping process, such as using an oxygen plasma or the like. Once the photoresist is removed, exposed portions of the seed layer are removed, such as by using an acceptable etching process, such as by wet or dry etching. The combination of the conductive material and remaining portions of the seed layer form the metallization pattern 116.
Next, the dielectric layer 118 is deposited on the metallization pattern 116 and dielectric layer 114. The dielectric layer 118 may have a material similar to the dielectric layer 114, and may be formed in a manner similar. The metallization pattern 120 is then formed. The metallization pattern 120 includes portions on and extending along the major surface of the dielectric layer 118. The metallization pattern 120 further includes portions extending through the dielectric layer 118 to physically and electrically couple the metallization pattern 116. The metallization pattern 120 may be formed in a similar manner and of a similar material as the metallization pattern 116. In some embodiments, the dielectric layer 122 is then formed over the dielectric layer 118 and the metallization pattern 120 in a similar manner to the dielectric layer 114, and a metallization pattern 124 is formed in and over the dielectric layer 122 and electrically coupled to the metallization pattern 120 in a similar manner to the metallization pattern 116.
Next, the dielectric layer 126 is deposited on the metallization pattern 124 and dielectric layer 122. The dielectric layer 126 may have a material similar to the dielectric layer 114, and may be formed in a manner similar. The metallization pattern 128 is then formed. The metallization pattern 128 may be formed in a similar manner to the metallization pattern 116 and may include a similar material as the metallization pattern 116. The dielectric layer 126 is the topmost dielectric layer of the redistribution structure 112, and the metallization pattern 128 is the topmost metallization pattern for external connections. In some embodiments, the metallization pattern 128 has bump portions on and extending along the major surface of the dielectric layer 126, and has via portions extending through the dielectric layer 126 to physically and electrically couple the metallization pattern 124. As a result, the metallization pattern 128 is electrically coupled to the first device die 50A. The metallization pattern 128 protrudes over the dielectric layer 126 in accordance with some embodiments.
It is appreciated that the first fan-out tier 101A may be substantially free of any through via in the encapsulant 110. In some embodiments, the first fan-out tier 101A has a thickness of 30 um to 700 um. Next,
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In some embodiments, an encapsulant 146 is formed over the redistribution structure 112 and may cover the top surfaces of the second device die 50B and the TIVs 140. The encapsulant 146 may include a material similar to the encapsulant 110, and may be formed in a similar manner. The encapsulant 146 may provide structural support for the second device die 50B and the TIVs 140. A planarization process may be used for exposing the device connectors of the second device die 50B and the TIVs 140. After the planarization process, a planarized top surface including the top surfaces of the second device die 50B, the TIVs 140, and the encapsulant 146 may be formed. The planarized top surface provides a planar platform for a redistribution structure to be formed thereon. The TIVs 140 may extend through the encapsulant 146. In some embodiments, the planarization process includes mechanical grinding, CMP, or other etch back technique.
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One or more third device dies 50C may be disposed over the redistribution structure 148 and adjacent to the TIVs 150 through an adhesive layer 154. The adhesive layer 154 may include a material similar to the adhesive layer 104. The third device die 50C may be the integrated circuit die 50 as illustrated in
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A redistribution structure 164 may be formed over top surfaces of the fourth device die 50D, the encapsulant 162, and the TIVs 160 in accordance with some embodiments, where the top surfaces of the fourth device die 50D, the encapsulant 162, and the TIVs 160 provides a planar platform for the redistribution structure 164 being formed thereon. The redistribution structure 164 may include materials similar to those of the redistribution structure 112, which may be formed in a similar manner, although the redistribution structure 164 may have a layout different from the redistribution structure 112. The redistribution structure 164 may include a top dielectric layer 166 and a top metallization pattern 168. In some embodiments, the top metallization pattern 168 is referred to as under bump metallization (UBM) or contact pads. The top metallization pattern 168 may protrude over or be level with the major surface of the top dielectric layer 166. In some embodiments, the fourth fan-out tier 101D has a thickness similar to that of the first fan-out tier 101A.
Conductive connectors 170 may be disposed over the top metallization pattern 168 of the redistribution structure 164, and the redistribution structure 164 may provide electrical connection to such conductive connectors 170. The conductive connectors 170 may be ball grid array (BGA) connectors, controlled collapse chip connection (C4) bumps, micro bumps, metal pillars, electroless nickel-electroless palladium-immersion gold technique (ENEPIG) formed bumps, a combination thereof, or the like. The conductive connectors 170 may include a conductive material such as solder, copper, aluminum, gold, nickel, silver, palladium, tin, the like, or a combination thereof.
After the formation of the conductive connectors 170, a singulation process may be performed to singulate the semiconductor device 100 from adjacent semiconductor devices 100. In some embodiments, each semiconductor device 100 is an individual device package as illustrated in
Each of the device dies 50A-50D may communicate with each other through the TIVs 140, 150, 160 and the redistribution structures 112, 148, 156, and 164. The device dies 50A-50D may be substantially free of through substrate vias (TSVs), which may reduce the silicon asset penalty and manufacturing costs. The TIVs may also have better thermal dissipation performance because they can have a greater size than TSVs. In some embodiments, the semiconductor device 100 as illustrated in
In some embodiments, processing of manufacturing the semiconductor device 100 proceeds according to processes similar to those described for
The redistribution structure 204 may be formed over the carrier substrate 202. The redistribution structure 204 may be substantially similar to redistribution structure 112 both in formation process and composition, and with greater sizes of the metallization pattern and a different layout. In some embodiments, as illustrated in
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In some embodiments, the encapsulant 212 includes a first portion 212A and a second portion 212B. The first portion 212A of the encapsulant 212 may be disposed over (e.g., in physical contact with) the redistribution structure 204 and surround the semiconductor device 100 and the device die 50E. The second portion 212B of the encapsulant 212 may fill the recess 180. The second portion 212B of the encapsulant 212 may be disposed over the inactive surface of the first device die 50A and surrounded by the encapsulant 110 in the first fan-out tier 101A. In some embodiments, the second portion 212B of the encapsulant 212 has a thickness and width same as the depth and width as the recess 180 (see
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In some embodiments, a passive device 230 is attached to a second side of the redistribution structure 204 and between the conductive connectors 222. The passive device 230 may be bonded to the bottom metallization pattern of the redistribution structure 204. The passive device 230 may be an integrated passive device, which may include capacitors, inductors, and/or resistors. In some embodiments, the passive device 230 includes a capacitor that is electrically coupled to the semiconductor device 100 and the device die 50E. The passive device 230 may enhance the performance of the integrated package 200, though it may be omitted. A singulation process may be performed to singulate the integrated package 200 from adjacent integrated packages 200.
The package component 220 may then be attached to a second side 204B of the redistribution structure 204 of the integrated package 200 (after singulation) through the conductive connectors 222. The package component 220 may include other device dies, interposers, package substrates, printed circuit boards, a mother board, and the like. In some embodiments, conductive connectors 232 may be disposed over a side of the package component 220 opposite to the redistribution structure 204. The package component 220 may be further attached to the other package components (not shown), such as package substrates, printed circuit boards, a mother board, and the like. In some embodiments, the conductive connectors 232 may include a material similar to the conductive connectors 222, except with greater sizes.
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In some embodiments, the active surface of the device die 50F and the active surface of the device die 50H face each other. The die connectors 66 of the device dies 50F and 50G may be aligned to and bonded to each other by, for example, an anneal process. The dielectric layers 68 of the device dies 50F and 50G may be aligned to and bonded to each other by, for example, the anneal process. As such, the device dies 50F and 50G are bonded by hybrid bonding (e.g., fusion bonding). In some embodiments, after the hybrid bonding is formed, an interface between the die connectors 66 of the device dies 50F and 50G becomes indistinguishable. In some embodiments, after the hybrid bonding is formed, an interface between the dielectric layers 68 of the device dies 50F and 50G becomes indistinguishable.
In some embodiments, the device die 50F may further include through substrate via 412 (TSV, or alternatively referred to as through silicon via) penetrating through the semiconductor substrate 52 of the device die 50F so as to electrically couple the die connectors 66 to the conductive connectors 210 on a side of the semiconductor substrate 52 opposite to the die connectors 66. As such, the device die 50G may be electrically coupled to the semiconductor device 100 through, for example, the TSVs 412 and the redistribution structure 204. The semiconductor device 402 and the semiconductor device 100 may be encapsulated by the encapsulant 212. The encapsulant 212 includes the first portion that surrounds the semiconductor device 402 and the semiconductor device 100 in accordance with some embodiments.
In some embodiments in which the semiconductor device 402 has a thickness greater than the semiconductor device 100 when attaching to the redistribution structure 204, a planarization process may be performed to level the top surfaces of the semiconductor device 402 and semiconductor device 100 after the encapsulant 212 is formed (e.g., the processing step described for
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In some embodiments in which the semiconductor device 402 has a thickness greater than the semiconductor device 100 when attaching the semiconductor device 402 to the redistribution structure 204, a planarization process may be performed to level the top surfaces of the semiconductor device 402 and semiconductor device 100 after the encapsulant 212 is formed (e.g., the processing step described for
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In accordance with some embodiments, an integrated package comprises a memory package and a logic device integrated over a redistribution structure. The memory package may include multiple fan-out tiers that use TIVs in lieu of TSVs for communication, which may reduce the silicon asset penalty and manufacturing costs. The memory package may include a logic die in one of its fan-out tiers for controlling the memory dies in other fan-out tiers. Alternatively, all the device dies in the memory package are memory dies, and these memory dies may be controlled by the logic device which is independent from the memory package in the integrated package.
In an embodiment, a package includes a first redistribution structure; a first semiconductor device attached to the first redistribution structure; a second semiconductor device attached to the first redistribution structure, wherein the second semiconductor device includes a second redistribution structure; a first device die disposed over the second redistribution structure and including an active surface facing the second redistribution structure; a first encapsulant extending along sidewalls of the first device die; a first through via extending through the first encapsulant; a third redistribution structure disposed over the first encapsulant, the third redistribution structure including a first metallization pattern connecting to the first through via; a second device die disposed over the third redistribution structure, wherein the first device die and the second device die are free of through substrate vias; and a second encapsulant extending along sidewalls of the second device die; and a third encapsulant disposed over the first redistribution structure and surrounding sidewalls of the first semiconductor device and the second semiconductor device, wherein a top surface of the third encapsulant is level with a top surface of the second encapsulant. In an embodiment, a top surface of the second device die is lower than a top surface of the second encapsulant. In an embodiment, the package further includes a fourth encapsulant disposed over the second device die and surrounded by the second encapsulant, wherein the third encapsulant and the fourth encapsulant are a same material. In an embodiment, a top surface of the fourth encapsulant is level with a top surface of the second encapsulant. In an embodiment, a width of the fourth encapsulant is greater than a width of the first device die. In an embodiment, a width of the fourth encapsulant is equal to a width of the first device die. In an embodiment, the package further includes a thermal interface material in physical contact with the second encapsulant, the third encapsulant, and the fourth encapsulant. In an embodiment, each of the first device die and the second device die has an active surface facing the first redistribution structure.
A package includes a first semiconductor device disposed over a first redistribution structure, wherein the first semiconductor device includes a first fan-out tier including a second redistribution structure; a first device die disposed over the second redistribution structure and including an active surface facing the second redistribution structure, wherein the first device die is a first memory die; a first encapsulant extending along sidewalls of the first device die; and a first through via extending through the first encapsulant and connecting to the first encapsulant. The first semiconductor device also includes a second fan-out tier disposed over the first fan-out tier, wherein the second fan-out tier includes a third redistribution structure disposed over the first encapsulant and the first through via; a second device die disposed over the third redistribution structure, wherein the second device die is a second memory die or a first logic die; and a second encapsulant extending along sidewalls of the second device die. The package also includes a second semiconductor device disposed over the first redistribution structure, wherein the second semiconductor device includes a second logic die; and a third encapsulant surrounding sidewalls of the first semiconductor device and the second semiconductor device, wherein a top surface of the third encapsulant is level with a top surface of the second encapsulant, and a top surface of the second device die is lower than the top surface of the third encapsulant. In an embodiment, the third redistribution structure is in physical contact with a top surface of the first encapsulant and a top surface of the first through via. In an embodiment, the package further includes an adhesive layer disposed between a top surface of the first device and the third redistribution structure. In an embodiment, the first encapsulant is free of through vias. In an embodiment, the second semiconductor device includes a die stack, wherein the die stack includes a third device die and a fourth device die, the third device die and the fourth device die being bonded through a hybrid bond. In an embodiment, the package further includes a third fan-out tier disposed between the first fan-out tier and the second fan-out tier, wherein the third fan-out tier includes a fourth redistribution structure disposed over the first encapsulant and the first though via; a third device die disposed over the fourth redistribution structure; a fourth encapsulant extending along sidewalls of the third device die; and a third through via extending through the through encapsulant, wherein a top surface of the third device die is lower than a top surface of the third through via. In an embodiment, the package further includes a dissipating structure laterally surrounding the first semiconductor device, the second semiconductor device, and the third encapsulant.
In an embodiment, a method includes attaching a first semiconductor device to a first redistribution structure; attaching a second semiconductor device to the first redistribution structure adjacent the first semiconductor device, wherein the second semiconductor device includes a second redistribution structure; a first device die disposed over the second redistribution structure; a first encapsulant extending along sidewalls of the first device die; and a first through via extending through the first encapsulant; a third redistribution structure over the first encapsulant and the first through via; a second device die disposed over the third redistribution structure; and a second encapsulant extending along sidewalls of the second device die. The method also includes forming a third encapsulant over the first redistribution structure and surrounding sidewalls of the first semiconductor device and the second semiconductor device. In an embodiment, the method further includes forming the second semiconductor device by attaching the second device die to a carrier through a first adhesive layer; forming the second encapsulant along the sidewalls of the second device die and the sidewalls of the first adhesive layer; forming the third redistribution structure over the second device die and the second encapsulant; forming the first through via over the third redistribution structure; attaching the first device die to the third redistribution structure through a second adhesive layer; forming the first encapsulant along the sidewalls of the first device die and the sidewalls of the second adhesive layer and surrounding the first through via; forming the second redistribution structure over the first device die and the first encapsulant; and removing the carrier and the first adhesive layer. In an embodiment, removing the carrier and the first adhesive layer forms a recess surrounded by the first encapsulant, wherein the recess is filled by the third encapsulant. In an embodiment, the method further includes removing a portion of the third encapsulant to separate the third encapsulant to a first portion and a second portion, wherein the first portion of the third encapsulant is surrounded by the first encapsulant. In an embodiment, the method further includes pressing the first device die or the carrier to make the first adhesive layer have a width greater than a width of the first device die.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
This application claims the benefit of U.S. Provisional Application No. 63/375,973, filed on Sep. 16, 2022, which application is hereby incorporated herein by reference.
Number | Date | Country | |
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63375973 | Sep 2022 | US |